[solved] Qt5 under Ubuntu cannot find -lGL

Just installed a copy of Ubuntu 12.04 and a "latest successful" build of the offline package of 5.0.1 and trying to run a simple test project I got this error message:

bq. /usr/bin/ld: cannot find -lGL

The "solution" I found on the Ubuntu forums was in Ubuntu/Linux specific terminology of which I, a Windows user, couldn't make anything useful, something about linkage being broken or the symbolic link being bad and having to remove the broken .so and associate the right files, without any ideas which are the broken ones, which are the right ones and so forth. There are plenty of libGL varying in sizes and versions.